added stripprefix support (#47)

requirements.txt

@@ -1,3 +1,3 @@
-ops == 1.5.3
+ops >= 2.0
 Jinja2==3.0.3
 typing_extensions

src/charm.py

@@ -8,7 +8,7 @@
 import textwrap
 from dataclasses import dataclass
 from itertools import starmap
-from typing import Iterable, Optional, Tuple
+from typing import Iterable, Optional, Tuple, cast
 from urllib.parse import urlparse
 
 import jinja2
@@ -62,7 +62,8 @@ class RouteConfig:
 
     root_url: str
     rule: str
-    id_: str
+    service_name: str
+    strip_prefix: bool = False
 
 
 @dataclass
@@ -107,7 +108,7 @@ def _check_var(obj: str, name):
         valid = starmap(_check_var, ((self.rule, "rule"), (self.root_url, "root_url")))
         return all(valid)
 
-    def render(self, model_name: str, unit_name: str, app_name: str):
+    def render(self, model_name: str, unit_name: str, app_name: str, strip_prefix: bool = False):
         """Fills in the blanks in the templates."""
 
         def _render(obj: str):
@@ -129,8 +130,10 @@ def _render(obj: str):
             rule = _render(self.rule)
 
         # an easily recognizable id for the traefik services
-        id_ = "-".join((unit_name, model_name))
-        return RouteConfig(rule=rule, root_url=url, id_=id_)
+        service_name = "-".join((unit_name, model_name))
+        return RouteConfig(
+            rule=rule, root_url=url, service_name=service_name, strip_prefix=strip_prefix
+        )
 
     @staticmethod
     def generate_rule_from_url(url) -> str:
@@ -229,8 +232,15 @@ def root_url(self) -> Optional[str]:
         """The advertised url for the charm requesting ingress."""
         return self._config.root_url
 
-    def _render_config(self, model_name: str, unit_name: str, app_name: str):
-        return self._config.render(model_name=model_name, unit_name=unit_name, app_name=app_name)
+    def _render_config(
+        self, model_name: str, unit_name: str, app_name: str, strip_prefix: bool = False
+    ):
+        return self._config.render(
+            model_name=model_name,
+            unit_name=unit_name,
+            app_name=app_name,
+            strip_prefix=strip_prefix,
+        )
 
     def _on_config_changed(self, _):
         """Check the config; set an active status if all is good."""
@@ -297,13 +307,15 @@ def _config_for_unit(self, unit_data: RequirerData) -> RouteConfig:
         #   if self._is_ready()...
         unit_name = unit_data["name"]  # pyright: ignore
         model_name = unit_data["model"]  # pyright: ignore
+        strip_prefix = bool(unit_data.get("strip-prefix", None))
 
         # sanity checks
         assert unit_name is not None, "remote unit did not provide its name"
         assert "/" in unit_name, unit_name
 
         return self._render_config(
             model_name=model_name,
+            strip_prefix=strip_prefix,
             unit_name=unit_name.replace("/", "-"),
             app_name=unit_name.split("/")[0],
         )
@@ -339,12 +351,16 @@ def _update(self):
 
     @staticmethod
     def _generate_traefik_unit_config(route_config: RouteConfig) -> "UnitConfig":
-        rule, config_id, url = route_config.rule, route_config.id_, route_config.root_url
+        rule, service_name, url = (
+            route_config.rule,
+            route_config.service_name,
+            route_config.root_url,
+        )
 
-        traefik_router_name = f"juju-{config_id}-router"
-        traefik_service_name = f"juju-{config_id}-service"
+        traefik_router_name = f"juju-{service_name}-router"
+        traefik_service_name = f"juju-{service_name}-service"
 
-        config: "UnitConfig" = {
+        config = {
             "router": {
                 "rule": rule,
                 "service": traefik_service_name,
@@ -354,16 +370,30 @@ def _generate_traefik_unit_config(route_config: RouteConfig) -> "UnitConfig":
             "service": {"loadBalancer": {"servers": [{"url": url}]}},
             "service_name": traefik_service_name,
         }
-        return config
+
+        if route_config.strip_prefix:
+            traefik_middleware_name = f"juju-sidecar-noprefix-{service_name}-service"
+            config["middleware_name"] = traefik_middleware_name
+            config["middleware"] = {"forceSlash": False, "prefixes": [f"/{service_name}"]}
+
+        return cast("UnitConfig", config)
 
     @staticmethod
     def _merge_traefik_configs(configs: Iterable["UnitConfig"]) -> "TraefikConfig":
+        middlewares = {
+            config.get("middleware_name"): config.get("middleware")
+            for config in configs
+            if config.get("middleware")
+        }
         traefik_config = {
             "http": {
                 "routers": {config["router_name"]: config["router"] for config in configs},
                 "services": {config["service_name"]: config["service"] for config in configs},
             }
         }
+        if middlewares:
+            traefik_config["http"]["middlewares"] = middlewares
+
         return traefik_config  # type: ignore
 
 

src/types_.py

@@ -4,7 +4,7 @@
 
 """Types for TraefikRoute charm."""
 
-from typing import List, Mapping
+from typing import List, Mapping, Optional
 
 try:
     from typing import TypedDict
@@ -36,11 +36,22 @@ class Service(TypedDict):  # noqa: D101
     loadBalancer: Servers  # noqa N815
 
 
+class StripPrefixMiddleware(TypedDict):  # noqa: D101
+    forceSlash: bool  # noqa N815
+    prefixes: List[str]
+
+
+class Middleware(TypedDict):  # noqa: D101
+    stripPrefix: StripPrefixMiddleware  # noqa N815
+
+
 class UnitConfig(TypedDict):  # noqa: D101
     router_name: str
     router: Router
     service_name: str
     service: Service
+    middleware_name: Optional[str]
+    middleware: Optional[Middleware]
 
 
 class Http(TypedDict):  # noqa: D101

tests/scenario/test_route_interface.py

@@ -0,0 +1,70 @@
+import pytest
+import yaml
+from charm import TraefikRouteK8SCharm
+from scenario import Context, Relation, State
+
+
+@pytest.fixture
+def ctx():
+    return Context(TraefikRouteK8SCharm)
+
+
+@pytest.mark.parametrize("strip_prefix", (True, False))
+def test_config_generation(ctx, strip_prefix):
+    ipu = Relation(
+        "ingress-per-unit",
+        remote_units_data={
+            0: {
+                "port": "81",
+                "host": "foo.com",
+                "model": "mymodel",
+                "name": "MimirMcPromFace/0",
+                "mode": "http",
+                "strip-prefix": "true" if strip_prefix else "false",
+                "redirect-https": "true",
+                "scheme": "http",
+            }
+        },
+        remote_app_name="prometheus",
+    )
+
+    route = Relation("traefik-route", remote_app_name="traefik")
+
+    state = State(
+        leader=True,
+        config={
+            "root_url": "{{juju_model}}-{{juju_unit}}.foo.bar/baz",
+            "rule": "Host(`{{juju_unit}}.bar.baz`)",
+        },
+        relations=[ipu, route],
+    )
+
+    state_out = ctx.run(ipu.changed_event, state)
+    route_out = state_out.get_relations("traefik-route")[0]
+    strip_prefix_cfg = {
+        "middlewares": {
+            "juju-sidecar-noprefix-MimirMcPromFace-0-mymodel-service": {
+                "forceSlash": False,
+                "prefixes": ["/MimirMcPromFace-0-mymodel"],
+            }
+        }
+    }
+    raw_expected_cfg = {
+        "http": {
+            "routers": {
+                "juju-MimirMcPromFace-0-mymodel-router": {
+                    "entryPoints": ["web"],
+                    "rule": "Host(`MimirMcPromFace-0.bar.baz`)",
+                    "service": "juju-MimirMcPromFace-0-mymodel-service",
+                }
+            },
+            "services": {
+                "juju-MimirMcPromFace-0-mymodel-service": {
+                    "loadBalancer": {"servers": [{"url": "mymodel-MimirMcPromFace-0.foo.bar/baz"}]}
+                }
+            },
+            **(strip_prefix_cfg if strip_prefix else {}),
+        }
+    }
+
+    assert route_out.local_app_data == {"config": yaml.safe_dump(raw_expected_cfg)}

tox.ini

@@ -70,10 +70,18 @@ deps =
     -r{toxinidir}/requirements.txt
 commands =
     coverage run --source={[vars]src_path} \
-        -m pytest --ignore={[vars]tst_path}integration -v --tb native -s {posargs}
+        -m pytest -v --tb native -s {[vars]tst_path}unit {posargs}
     coverage report
 
 [testenv:scenario]
+description = Run integration tests
+deps =
+    pytest
+    jsonschema
+    ops-scenario>=5.0
+    -r{toxinidir}/requirements.txt
+commands =
+    pytest -v --tb native --log-cli-level=INFO -s {[vars]tst_path}scenario {posargs}
 
 [testenv:integration]
 description = Run integration tests
@@ -84,4 +92,4 @@ deps =
     pytest-operator
     -r{toxinidir}/requirements.txt
 commands =
-    pytest -v --tb native --ignore={[vars]tst_path}unit --log-cli-level=INFO -s {posargs}
+    pytest -v --tb native --log-cli-level=INFO -s {[vars]tst_path}integration {posargs}